Florida declares state of emergency ahead of Hurricane Irma

Irma, a still strengthening and dangerous Category Four hurricane, churned toward the Leeward Islands early Tuesday, sparking alarm and alerts from the Caribbean to Florida, which declared an emergency.

The National Hurricane Center said at 0300 GMT that the storm was packing top sustained winds of 140 mph (220 km/h). "Additional strengthening is forecast during the next 48 hours," the NHC warned.

The threat comes as Texas and Louisiana are still cleaning up from disastrous flooding caused by mighty Hurricane Harvey last weekend.

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Irma's center was about 410 miles (660 kilometers) east of the Leeward Islands, grinding westward at 13 miles per hour (20 kilometers per hour) the NHC said.

"On the forecast track, the center of Irma will move near or over portions of the northern Leeward Islands Tuesday night and early Wednesday."

"Preparations to protect life and property should be rushed to completion," it stressed.

A Category Four storm on the Saffir Simpson scale is capable of doing widespread major structural and infrastructure damage; it can easily tear off roofing, shatter windows, uproot palm trees and turn them into projectiles that can kill people.

Category four strength was the maximum attained by Harvey, which dumped as many as 50 inches of rain in some parts of Houston, turning neighborhoods into lakes.

Irma is projected to reach the Leeward Islands of the Lesser Antilles chain by late Tuesday or early Wednesday, bringing water levels up to 9 feet (3 meters) above normal levels, rainfall of up to 10 inches (25 centimeters) in areas, and "large and destructive waves."

In Puerto Rico, a US territory of 3.5 million, Governor Ricardo Rossello activated the National Guard and announced the opening of storm shelters able to house up to 62 000 people. Schools will be closed Tuesday.

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